Pyrolytic decomposition of hydrocarbons



Filed Feb. 2'7, 1928 Patented July 12, 1932 rm: 1!. ovrrz. or wm'mre:mung-manor 'ro erammnn on. courm, or

wmrme, nmnuu, a ooarom'rrou or mnnum momma nnoourosrrrou or none cannonsAmman; mar rem-mi am nes. senor. 257,854.

This invention relates to yrolitic decomposition of hydrocarbons an'particularly to theprevention t corrosion of the metallic apparatusemployed for suchdeoom o' sition. he invention willreadily be an erstcodfrom the following description in 0l1nootion withthe accompanyingdrawing which shows diagrammatically an apparatus whereby hy- "char'coillO. The outlet of the heating coil' 10 leads into theconversion'chaniber '11,

which is maintainedat a desired cracking".

drocarbon oils may be pyrolptically decomposed and the resulting proucts recovered.

Referringto'the drawing, 10 is a heating coil;'-11 is a retorfiorconversion-chamber;

12-is the refluxcondenser for overhead from said chamber; 13 is aflashdrum for tar from chamber 11 14 is a filter for the residue from saidflash drum; 1.5 is a fractionating com denser for the overhead from theflash drum; 16 is a receiver for the bee "condensate therefrom; 17, is atank in whlch a ortion p of said condensate is adapted to be c :11 edwith hydrated iron oxide; and 18 is :a eed pipe leading to the heatingcoil 10. w a

A mp 19 is provided for supplying g stock under pressure to the eatingtemperature by burners 21. The; convers on chambrdl 1s suitably-providedwith a.

flux' condenser with suitable scraper 40 for the of. removing cokeiorming material rom the walls thereof and oausin' it to fall to thebottom of thechammm the upper end of the conversion 22 leads to the re-O 0., v- Q ftfitlonatlilgi-mid oondensi devices (not she condenser 12through line 28 by 'ump 2'3 toithe heating coil 10; Frointhe ower end ofthe conversion chamber 11- a pi e'24-lead's to the dash drum 13, saidpipe 24' eing rovided witha valve 25. From the top o the drum13 a pipe'2firleads to thejlower artline 38;

A vapor pipe 42- lea s fromthe to of the iractionating condenser 12 to asuite l'e condenser (not shown). Re- 11111: condensate may berreturnedfrom the thiscondenser a pipe QT'Ieadsinto.

the receiver-16 and fromthe-to thereof a pipe 43 leads toa suitable conenser (not shown From the'underside of the drum 13 a P1pe28 leads .intothe filte'r14. A suitable pump,'for example, at hot oil pump29 isprovided in the line 28 for forcing 'thepressure tar residuum into thefilter 14.

The filtered pressure tar residuumpasses V from the filter 14 by pipe30.

Theheav pressure tar distillate receiver '60,

y The tank 17 is providedfwith a perforated on pipe 34 which is adaptedto inject air into the contents' thereof. From a low position on-thetank 17,'a pipe 35,1eads to the upper ortion of said tank.- Said pipe 35is provided with'a circulating ump 36'and a hop .70

per 37 b means of yv ieh hydrated iron oxide an other substances such aswater,

may be added to the oil circulated bythe pump 36 and may thereby bedisseminated throughout the oil in tank 17. From the bottom of tank 17,'a' pipe 38 leads into the feed lihe18.

'Theoperat-ion follows:

Heavy pressure tar distillate g mp 3- v h d -o tillate is thencirculated through the 35 by pump 36 from-thebottom tothe top of the yatank 17. 'Hydrated iron oiiide; in finel divided foi'm is fed into thecirculating 011 y by the hopper ;37 and is carried by the oil"-culati'ng oil by the hopper' 37 andis'c'arried' by theeirculatingoil'into tank 17. A pertain amount of .water may then )be. suppliedhopper'37, if desired, said water assisting also. preferablywhile it isbeing usedrthe'oil in the tank 'l'l is agitated by air introduced bytheperforated pipe 34." It is preferred to;

produce irithis manner a'suspensionof ironoxide-containingiapproximately1,5 lbs! per 1 9,

A pump 89'i's'prov ided the v 4 islr p .from receiver 16 through line 32by into tank 17 until it is nearly full somewhat in the production of asatisfactory. suspension-of the ironoxide in the oil.

While the suspension is being produbedjandg 5 gallon. The amount ofwaterused may suitabl be about 0.8% b volume of the 011.

he charging stoc which is supplied to the heating 0011 10 through line18 by the pump 19 mal be any suitable hydrocarbon oil heavier t angasoline, such as gas oil, garaiiin light ends, pressure tar distillate,eavy paraflin distillate, or mixtures of two or more thereof. The oilcontaining suspended hydrated iron oxide is fed to the charging stockthrough line 38 by the pump 39 in quantity suflicient to provide asuitable oxide content in the oil passing through the heating coil 10and conversion chamber 11. A suitable quantity of oxide is approximately0.5 lbs. per arrel of charging stock i. e. about 0.17% by weight. Itmust be understood that this amount will vary with stocks of differentcharacter and origin, but the proportion of such oxide ordinarily willnot exceed a fraction of 1% relative to the wei ht of the oil.

e temperature and pressure conditions in the heating coil 10 and theconversion chamber 11 may var within wide limits. For example, the outet temperature of the heating coil 10 may suitably be about 820 to 850F. and the pressure may suitably be about 325 to 400 lbs. per squareinch. The chamber 11 may be heated by the burners 21 to maintain asuitable cracking temperature therein.

The fractionating condenser 12 is controlled to give a pressuredistillate of the desired character, the vapors of which pass off bypipe 42 and are condensed. The reflux from condenser 12 is returned tothe heating coil 10 through pi e 23 by ump 23.

Pressure tar 1s rawn oil from the bottom of chamber 11 and isaccompanied by more or less coke which is reduced in the oil, as well asiron oxide an iron sulfide which are disseminated in solid form in thecoke and in the tar. The withdrawal is effected con' tinuously, orperiodically, through the valve 25 and pipe 24 and the tar is flashed inthe drum 13 which is maintained substantially at atmospheric pressure.The overhead passes by a pipe 26 to the fractionating condenser 15 inwhich the heavy pressure tar distillate is condensed, the condensatepassing by pipe 24 to the receiver 16. The light pressure tar distillatevapors pass by pipe 43 to a suitable condenser (not shown).

Ordinarily, only a small part of the heavy pressure tar disti late isused in the tank 17 or the production of the suspension of iron oxide inoil; the remainder is withdrawn by pipe ,31 to be used in producingblended charged stock.

The ressure tar residue is pumped in a hot condition through pipe 28 bypump 29 into the filter 14. Ordinarily it is preferred to use a pressurefilter,'but an other filter may be used. Among others, ters of theSweetland and Kelly type are suitable. The filter surfaces may suitablybe constituted by woven metal, such as fabrics woven from steel, copper,brass or other suitable metallic wire.

The hydrated iron oxide combines with the sulfur and sulfur-com oundswhich exert a corrosive elfect upon the metal of the ap aratus so thatinternal corrosion from t is cause is substantially prevented. Theproportion of hydrated iron oxide is so small that the fluidity of theoil undergoing treatment is not substantially im aired. Further, the hdrated iron oxide an iron sulfide produce therefrom, together with thecoke, constitute a suitable filter medium which materiall aids inpreventingpassage of other soli material while permitting the liquidginstitunt of the tar to pass through the ter.

While I prefer to employ hydrated iron oxide, it must be understood thatiron oxides and other oxygenated compounds such as carbonates, whichwill react with sulfur and sulfur compounds under the conditions of theoperation, may be employed in finely divided form according to theinvention.

Although the present invention has been described in connection with thedetails of a specific embodiment thereof, it is not intended that suchdetails should be regarded as limitations on the scope of theinventionexcept in so far as included in the accompanying claims.

I claim:

1. In the art of converting hi her boiling hydrocarbon oils into lowerboilin hydrocarbon oils wherein such oil is sub ected to crackingconditions of temperature and pressure while confined within metallicapparatus, the method of reducing corrosion of said metallic apparatusby the said oil undergoing cracking which comprises maintaining in thepresence of said Oll under oing conversion, hydrated iron oxide in t 1eamount of not more than a fraction of 1%.

2. In the art of converting higher boilin hydrocarbon oil wherein suchoil is subjecte to cracking conditions of temperature while flowingthrough a confined metallic passageway and is passed therefrom while ata cracking temperature to an enlarged metallic chamber wherein itundergoes further cracking, the method of retarding corrosion of saidmetallic passageway and said metallic chamher by the said oilundergoingcracking,which comprises admixing with the oil, prior to itsintroduction into said metallic passageway, not more than a fraction of1% of hydrated iron oxide.

3.- In the art of converting higher boiling hydrocarbon oils into lowerboiling hydrocarbon oils wherein such oil issubjected to crackingconditions of temperature and pressure while confined within metallicapparatus,

the method of reducing corrosion of said metallic apparatus by the saidoil undergoing cracking which comprises maintaining 1n the presence ofsaid oil, undergoing conversion an amount of not more than a fraction 01% of h%drated iron oxide substantially free of absor ed alkali.

4. In the art of converting higher boiling hydrocarbon oils into lowerbollin hydrocarbon oils wherein such oil is sub ected to crackingconditions of temperature while flowing through a confined metallicpassageway, said oil bein passed from said passageway while at crac mgtemperature to an enlarged metallic chamber wherein it undergoes furthercracking, the vaporous products of conversion and the heavy liquidresidual products of conversion being separately withdrawn from saidchamber and the latter products being assed through a filter element,the method 0 retarding corrosion of said metallic passageway and chamberby the said oil undergoing cracking, which comprises admixing with theoil, prior toits introduction into said passageway, not more than afraction of 1% of hydrated iron oxide.

5. The method of decomposing hydrocarbon oils w' 'ch com rises crackingthe oil under pressure, wit drawin liquid products and assing t em to azone of lower" pressure w erein light and hea fractions are formed,mixing 1101'1 oxide wit said light fractions, and rethrning said mixture to the oil being cracked.

In witness whereof I haveunto set my hand this 9th day of February 1928.

FRAN K. OVITZ.

unvaporized CERTIFICATE OF CORRECTION.

Patent No. 1,866,666.

July '12, 1932.

FRANK K. OVITZ.

it is herebycertified that error appears in the printed specification ofthe above numbered patent requiring correction as follows: Page 1, line55, for "at" read a; same page, lines 58 and 59, should not appear as aseparate paragraph but should follow' "filter 14." in line 57; line 83,for "the" read pipe; and lines 88 and 89, strike out the words "by thehopper 37 and is carried by the circulating oil"; and that the saidLetters lfatent should be read with these correctiohs therein that thesame may conform to the record 'of the case in the Patent Office.

Signed and sealed this 1st day of November, A. D. 1932.

(Seal) Mu]. Moore, Acting Commissioner of Patents.

the method of reducing corrosion of said metallic apparatus by the saidoil undergoing cracking which comprises maintaining 1n the presence ofsaid oil, undergoing conversion an amount of not more than a fraction 01% of h%drated iron oxide substantially free of absor ed alkali.

4. In the art of converting higher boiling hydrocarbon oils into lowerbollin hydrocarbon oils wherein such oil is sub ected to crackingconditions of temperature while flowing through a confined metallicpassageway, said oil bein passed from said passageway while at crac mgtemperature to an enlarged metallic chamber wherein it undergoes furthercracking, the vaporous products of conversion and the heavy liquidresidual products of conversion being separately withdrawn from saidchamber and the latter products being assed through a filter element,the method 0 retarding corrosion of said metallic passageway and chamberby the said oil undergoing cracking, which comprises admixing with theoil, prior toits introduction into said passageway, not more than afraction of 1% of hydrated iron oxide.

5. The method of decomposing hydrocarbon oils w' 'ch com rises crackingthe oil under pressure, wit drawin liquid products and assing t em to azone of lower" pressure w erein light and hea fractions are formed,mixing 1101'1 oxide wit said light fractions, and rethrning said mixture to the oil being cracked.

In witness whereof I haveunto set my hand this 9th day of February 1928.

FRAN K. OVITZ.

unvaporized CERTIFICATE OF CORRECTION.

Patent No. 1,866,666.

July '12, 1932.

FRANK K. OVITZ.

it is herebycertified that error appears in the printed specification ofthe above numbered patent requiring correction as follows: Page 1, line55, for "at" read a; same page, lines 58 and 59, should not appear as aseparate paragraph but should follow' "filter 14." in line 57; line 83,for "the" read pipe; and lines 88 and 89, strike out the words "by thehopper 37 and is carried by the circulating oil"; and that the saidLetters lfatent should be read with these correctiohs therein that thesame may conform to the record 'of the case in the Patent Office.

Signed and sealed this 1st day of November, A. D. 1932.

(Seal) Mu]. Moore, Acting Commissioner of Patents.

